If people abide by natural selection, active developed mods that are actually in progress will push to the front of the pages, dead/inactive mods will fall to the wayside and further down, when they resurface and are clearly dead we just close them for what they are... Then they fall the wayside again, why change what ain't broke?
As to the theory it is easy to move things... If you follow every topic and know who's done what perhaps it's easy to know who's active mods are released and whos aint... Most of us don't do that so Idk who all's things are released and whos are not.. IF everyone was kind enough to put all pertinent info in the first post of a topic including download links then it would be pretty easy but even still we'd have to verify the download links work and all that sort of thing, that is a bit above and beyond our job title since simply put alotta things are hosted off-site it isnt as easy to prune topics for released/not.. Now I could very easy go by date of active posts or something of that sort but why bother? In there are some released but inactive mods that someone made some time ago but no longer bother to update, thus their topics fall down in the ranks, not much I can do about that one but if I pruned the topics they'd end up in WIP even though they werent...
To me worrying about clean-up is better served when someone is really really bored and wants to vet through the mess, if people went over to the courtesy of using the first post for the basic info of the mod/download links it would make it alot easier to refer people there IF they are indeed released. As time goes on natural selection will bump the not so useful topics out of line and imo that is a suitable trend for now... I don't see a value in overdoing it, this concept is more to help in the future, not change the past.
